Big Block Chevrolet
Intake Manifold Casting Numbers
Alloy Recangular Port (Execpt where noted)

3805069	1966 - 68	396	375hp	L-89 / L-78
3866963	1965	396	375hp	L-37
3885069	1966	427	425hp	L-72
3886093	1967	427	430hp	L-88
3894374	1967	427	435hp (3 x 2 barrel)	L-71
3894382	1967	427 (oval port)	400hp (3 x 2 barrel)	L-68
3919850	1968	427 (oval port)	400hp (3 x 2 barrel)	L-68
3919852	1968	427	435hp (3 x 2 barrel)	L-71
3933164	1968 - 69	396 427	375hp 425hp	L-78 / L-89 COPO
3933198	1969	427	430hp	ZL-1
3937795	1969	427 (oval port)	435hp (3 x 2 barrel)	L-68
3937797	1969	427	435hp (3 x 2 barrel)	L-71
3963569	1970 - 91	396 / 402 454	375hp	L-78 / L-89 LS-6
3967474	1971	454	425hp

Cast Iron Oval Port

3966948	1966 - 67	396 427	360hp (Holley) 390hp (Holley)	L-34
3883948	1966 - 68	396	325hp (Q Jet)	L -35
3931067	1969	396	325hp (Q Jet)	L -35
3955287	1970 - 71	402	330hp (Q Jet)	LS-3
6263753	1972	402	240hp (Q Jet)	LS-3